Structural basis for activation, assembly and membrane binding of ESCRT-III Snf7 filaments

  1. Shaogeng Tang
  2. W Mike Henne
  3. Peter P Borbat
  4. Nicholas J Buchkovich
  5. Jack H Freed
  6. Yuxin Mao
  7. J Christopher Fromme
  8. Scott D Emr  Is a corresponding author
  1. Cornell University, United States
  2. The University of Texas Southwestern Medical Center, United States
  3. The Pennsylvania State University College of Medicine, United States

Abstract

The endosomal sorting complexes required for transport (ESCRTs) constitute hetero-oligomeric machines that catalyze multiple topologically similar membrane-remodeling processes. Although ESCRT-III subunits polymerize into spirals, how individual ESCRT-III subunits are activated and assembled together into a membrane-deforming filament remains unknown. Here, we determine X-ray crystal structures of the most abundant ESCRT-III subunit Snf7 in its active conformation. Using pulsed dipolar electron spin resonance spectroscopy (PDS), we show that Snf7 activation requires a prominent conformational rearrangement to expose protein-membrane and protein-protein interfaces. This promotes the assembly of Snf7 arrays with ~30Å periodicity into a membrane-sculpting filament. Using a combination of biochemical and genetic approaches, both in vitro and in vivo, we demonstrate that mutations on these protein interfaces halt Snf7 assembly and block ESCRT function. The architecture of the activated and membrane-bound Snf7 polymer provides crucial insights into the spatially unique ESCRT-III-mediated membrane remodeling.

Article and author information

Author details

  1. Shaogeng Tang

    Weill Institute of Cell and Molecuar Biology, Cornell University, Ithaca, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. W Mike Henne

    Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Peter P Borbat

    National Biomedical Center for Advanced Electron Spin Resonance Technology, Cornell University, Ithaca, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Nicholas J Buchkovich

    Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Jack H Freed

    National Biomedical Center for Advanced Electron Spin Resonance Technology, Cornell University, Ithaca, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Yuxin Mao

    Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. J Christopher Fromme

    Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, United States
    Competing interests
    The authors declare that no competing interests exist.
  8. Scott D Emr

    Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, United States
    For correspondence
    sde26@cornell.edu
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. William I Weis, Stanford University, Bangladesh

Publication history

  1. Received: October 24, 2015
  2. Accepted: December 13, 2015
  3. Accepted Manuscript published: December 15, 2015 (version 1)
  4. Version of Record published: January 13, 2016 (version 2)

Copyright

© 2015, Tang et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Shaogeng Tang
  2. W Mike Henne
  3. Peter P Borbat
  4. Nicholas J Buchkovich
  5. Jack H Freed
  6. Yuxin Mao
  7. J Christopher Fromme
  8. Scott D Emr
(2015)
Structural basis for activation, assembly and membrane binding of ESCRT-III Snf7 filaments
eLife 4:e12548.
https://doi.org/10.7554/eLife.12548
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